create snap readme; add go install github.com/digitalocean/github-cha…

…ngelog-generator@latest

==> list merged PRs since last release to review changes to release

CONTRIBUTING.md

@@ -194,9 +194,13 @@ to do so. Travis also runs shellcheck.
 
 ## Releasing
 
-1. Use [github-changelog-generator](https://github.com/digitalocean/github-changelog-generator) 
- to list the changes since the last release 
- and decide what kind of release you are doing (bugfix, feature or breaking).
+To cut a release, push a new tag (versioning discussed below).
+
+### Tagging a release
+
+1. Run `make changes` to review the changes since the last
+ release. Based on the changes, decide what kind of release you are
+ doing (bugfix, feature or breaking).
  `doctl` follows [semantic versioning](https://semver.org), ask if you aren't sure.
 
 1. Synchronize your local repository with all the tags that have been created or updated on the remote main branch

snap/README.md

@@ -0,0 +1,20 @@
+# Snap
+
+Snap packages are automatically built and uploaded as part of the GitHub Actions
+release workflow.
+
+To build a snap package locally for testing, first install `snapcraft`.
+
+On Ubuntu, run:
+
+ sudo snap install snapcraft --classic
+
+Or on MacOS, run:
+
+ brew install snapcraft
+
+Finally, build the package by running:
+
+ make snap
+
+More details about the snap package can be found in the `snap/snapcraft.yaml` file.